Sewing-machine stitch-forming mechanism.



1. WHITELAW. SEWING MACHINE STITCH FORMING MECHANISM.

' APPLICATION FILED NOV. 24, I913.

Patented July 11, I916.

5 SHEETS-SHEET l llll (Rodi/ J. WHITELAW.

SEWING MACHINE STITCH FORMIJVG MECHANISM.

APPLICATION HLED NOV. 24. l9l3.

w W m m w P 1% l. WHITELAW. SEWING MACHINE STITCH FORMING MECHANISM.

APPLICATION FILED NOV. 24. 1913.

1,1 90,833. Patented July 11, 1916.

5 SHEETS-SHEET 3.

J5 Zl J. WHITELAW.

SEWING MACHINE smcu FORMING MECHANISM.

APPLICATION FILED NOV= 24. l9l3.

Patented July 11, 1916.

5 SHEETS-SHEET 4 James W/I/fe/aw I. WHITELAW.

SEWING MACHINE STITCH FORMING MECHANISM. APPLICATION FILEAD Nov. 24. 1913.

1,190,833. Patented July 11, 1916.

5 SHEETS-SHEET 5.

5U} M65525" Zia/6 74723 Wm. Q? Q I 424mm M STATES PATENT OFFICE.

' ames ,wHI'rELAwoF ST. LOUIS, MISSOURI,

SEWING-MKCHINE STITCH-FORMING MECHANISM.

To all whom it moyconcem Be; it known 'thatnI, James Wnrr snaw,

.a citizen of the- United States residing-at cation.

.oth'er variations. I

St; Louis, 'State Missouri, have invented certain new and useful Improvements in Sewing 7 Machine Stitch Forming Mecha-V nism, of which the following is specifi- My invention its features mor'e particularly to a sewing machine for'making-blind chain stitches.

()neof the objects of myinventionis to provide a loo'per mechanism particularly adapted forcoiiperation with a reciprocat ing needle to iorni chain stitches, which will -.be' certain and uniform/in its loophandling' functions-under"varying condi-e tionsr 'in t-he work, due" to different lengths of feed movement Another; object-pf invention is-xto provide such "a jloopermec'hanism of simple and eflicient structure, notifiable tofget out of order, ea-silymanufactured .andassembled,

and readily repaired, if damaged.

A further'objectof my invention is 'to' provide simple and effective coordination of the needle, looper, andtake-up mechanisms, and to-provide for the adequate-association of these parts a simple and'easilymanufactured mechanism.

In the draWings,-w herein I have illustrated an embodiment of my. invention in a form which I have found to-be practically advantageous, Figure 1 is a front elevation of a chain-blind-stitc'h machine, with parts of its stitch forming mechanism exposed;

1Fig. 2 is an enlarged front elevation. showing the stitch forming mechanism in greater detail; Fig.1 3" isa'smnlar endview of the stitch forming mechanism and appurtenant V parts; -Fig. 4 is a detail in vertical cross.

relates to-s ewing machine stitch forming mechanism, "and in some of hetween stitches,- and and looper relation two posit-ions,-illustrating respectively the loop taking and loop presenting operations'of the looper.

The frame 'lO of the machine is suitably designed to provide thelower work carry. 4 mg arm 11 and the upper arm 12 for earrying the stitch forming mechanism,- the frame of the machine being preferably a.

hollow integral casting open at. its front face and having the contained .mechanism protected by adequate detachable cover memb'ers13 and 13, thecover -13 being r'etaine'd as by latch screw and'cam, 1 1, 14.

e The goods are handled in the machine through the cooperation of a relatively Sill? Specification of Letters Patent. PatentedJuly' 11,- 1916. Application filed November 24, 1913, Serial No. 802,733. I

. tlonary presser foot 15 carr cdby the upperv arm and feeding mechanism carried by the lower arm and supplemented-by aplunger for elevating portions-of the goods through the presser. foot to the action .o f the needle. Specifically, the machin'e shown has at.its front end a vertical head post- 16"to 'vhiclr thepre'sser foot 1'5 issecured by screw j 17,

said presser foot extending transversely of the arm and having atitscenter an-opening 18 flanked on its under side by'solid' surfaces for the feedioworlragainst.

Fragments only-"of the work handling 'mechanism 19 are here shown, for, generically, feed mechanisms and plunger mechanisms sulhcient for the purposes of the prese'nt invention are lrnown'in the'art, and the p particular work handling. mechanism .which" I preferably employ is specificallydescribed in my co-pendmg. application, Serial No.

802,732, filed November 24th, 1913. It suf fices to say, therefore, that'the feed dog 20 cooperating with the under side of the stationary presser foot receives an appropriate four-way motion and is supplemented by a clamp member 21 raised to clamping position whenthe feed member is lo\vered and straddled by the limbs of thefeed dog, said clamp member having associated therewith a plunger 22 registering ,with the presser foot opening 18 and HDPXOPIlHt-Gly operated to raise the nodes (1 of the goods A through the prcsscr foot opening for codperat-ion with the needle 30 as shown in Fig. 8. In the cyclic operation of these parts wi h" spcct to the needle reciprocation, it will be understood, when the needle is retracted the plunger-rises through the prcsser foot opening to present a node of goods in tho I line of passage of the needle, the goods heing clamped against the under side of the presser foot by the clamp member 21. The

needle makes its penetrating stroke through such node of goods, entering and emerging from thesame surface of the work; when the penetration is completed the plunger descends, and upon. completion of; the retraction of the needle the clamp 21 also retracts and the feed dog 20 performs its for-. ward feeding motion, feeding the goods transversely across the lower arm from the front of the machine to the rear thereof;

' the feed disengaging the goods and the outer radius of curvature, and inclined to its path of reciprocation with its point 1 nearer the plunger than its butt. Said needle is mounted to reciprocate transversely of the direction of feed, preferably at right angles thereto. To receive'the' needle the upper surface of the presser foot is preferably dished or concaved and a needle deflecting guide 31 is mounted thereon, to deflect the needle point toward alinement with the path of reciprocation,'said guide having in its face a groove 31, the sides of the groove serving to prevent lateral displacement of the needle point.

The needle is carried by a needle bar 32 pivotally mounted on the frame post 16 vertically'above the presser foot opening 18 and said arm has an upwardly extending finger 33 through which oscillating motion is imparted to the bar. For the reception of a concentric shaft member of the looper mechanism to be described the hub of the needle bar 32 is provided or connected with a sleeve or hollow shaft 34taking through a bearing in the frame post 16 and itself affording a bearing for the concentric shaft. Motion is imparted to the needle bar by link 35 pivoted at 35" to the end of finger 33 and to a wrist pin 36 on a spiral gear wheel 37 carried by jack-shaft 38 which extends through the rear wall of the arm 12 to re ceive, beyond the rear Wall of the machine, other mechanisms to be described. The gear 37 is driven in one-to-one relation by a spiral gear 39 which is carried by a main shaft 40, said main shaft extending horizontally from end to end of the upper arm 12 and projecting through hushed bearings 1n both end walls thereof. At its rear end said shaft bears a suitable hand wheel pulley 40' for power application thereto. Manifestly with the arrangement described the needle reclprocates once for every revolution of the main shaft.

From themain shaft 40 the mechanism,

for actuating the looper bar structure 41 'is driven and timed While, for some of :the purpose of my invention, a looper bar havlng a single point may be employed, and

an operating mechanism asfhereafter'described 18 suitable for the operation of a single point looper, I find it to be distinctly advantageous to employ a looper having two points or members, one'of wlnch is 1 power moved in a six way path while the atoi; and beveled at its top. Pivoted to the member 43, as at 46, is a complemental looper member 47 in the form of a lever having its lowerarm shaped to provide a point 48 vertically registering with thetoe.

45, said point terminating at a shoulder 49, and the member 47 so disposed that, as shown in Figs. 7 and 8, when the two looper members are closed together the point 48 rests upon and projects beyond the extrempoint, and when the member 47 is rocked on its pivot 46 the point 48 separates from the toe and shoulder 49 stands about' in vertical alinement with the end of the foot 44. Member 47 has at its upper end a forwardly projecting finger 50 through which the opening movement is'given to the member 47 and a spring 51 connecting said finger with the projection 52 on the member 43 tends normally to hold the looper parts in closed position.

The looper-point structure 42 as a Whole is given a 6-way movement, fore-and-aft, -or lengthwise of the needle path topresent it to the needle at two points in the needle travel; in and out, or transversely to the needle path, for engagement with or disengagement from the loop, and up and down, to carry the loop above thepresser foot opening. For one component of its movement the looper bar 41 as a whole forms a lever of the first class and by movement of its upperend above its fulcrum, the in and out motions are'communicated to the ,looper point structure 42. Its fulcrum as ity of the toe 45 for the effect of a single such lever is shiftable fore-and-aft operatcarried by a fulcrum block 57 which is encompassed by the yoke. Above the yoke, the stem 58 forms a power receiving arm for in-and-out vibration and makes sliding engagement with the ball 59 socketed in a spherical recess in the extremity of a lever 60, such form of connection permitting universal displacement of the arm 58 with respect to its power lever 60 and making the end of lever 60 the fulcrum for the foreand-aft vibration. The lever 60 is pivoted on a longitudinally extending shaft 61 proectlng from a part on the frame post 16 whereon it is retained by a collar 62 and the power-receiving end of said lever 60 carries a roller 63 engaging in a cam groove 64 of a disk 65 mounted directly on the main shaft 40. Rotation of cam 65 acts through lever 60 to vibrate the upper end of the looper lever in and out, said looper lever rockingon the pins 56 and moving only in a plane transverse to the needle path.

The fulcrum block 57 on which the looper lever fulcrums has pivotal connection, between spacer collars 67, with the wrist pin 67 which is disposed eccentrically to its supporting shaft 68 taking through the bore of needle arm shaft 34'. A flange 69 on shaft 68 abuts against the needle arm and a gear pinion 70'is fastened on of the shaft, retaining it against displacement. Oscillation of shaft 68 to throw the wrist pin 67 past, its vertical center shifts the fulcrum black 57 fore-and'aft with respect to the plane of in and out motion of the universal joint 59 and so contributes fore-and-aft movement to the looper point structure, carried as a whole by shaft 68, while the vertical displacement of the wrist pin in such elevateand depress the looper point structime, it's stem 58 sliding accommodatingly in the ball 59. Motion is imparted to the pinion 70 by ageared segment 71 mounted on shaft 7 2 carried by the frame and having pivoted link connections 73 with a wheel 7 4 fast on the shaft 38, such connection serving to reverse the direction of motion of looper carrying shaft 68 with'respect to-needle bar shaf t 38, and to give to the rock shaft 68 the desired angular range of movement between its limits of throw.

The driving of both the needle bar and the means for imparting fore-and-aft motion to the looper from the same jack-shaft 38 by wheels fast thereon insures perfect harmony in the movement of the needle and loo er in the direction of needle travel; elevation and depression of the looper bythe eccentric pin 67 insures accurate positionbutt of the looper point structure vertically with respect to the needle path at each end of its fore-and-aft and the operation of the loopgg so that the looper may the rear extremity oscillating traverse serves to nnnm bar rapidly on the main shaft permits-by the variability of the shape of the cam slot to give any cam pitch desired, that the velocity at which, the looper point structure moves to engage and disengage the loops may be made whatever may be desired to insure most effective operation, and the extent of in-and-out throw being similarly defined as desired. In setting and timing these parts, wrist pin 67 is made to throw a little farther over center one way than the other, so that while the relatively rigid looper point is brought below the arc of needle passage at one end .of its throw it stops above the needle line at the other end of its throw, and link 73 is arranged to pass dead-center while the looper is at the ends of its throw, dwell materially at the extremes of its fore-and-aft movement.

To cause the looper to spread the loop for reception of the needle I mount upon the post 16 a stationary cam 7 6 formed as an L-shaped arm having its upper cam surface 77 disposed in the path of travel of the finger 50 of the pivoted looper member 47, so that as the looper moves from right to left (Fig. 2) or down and aft toward the retracted position of the needle, the finger 50 striking on the upper edge of cam 76, tilts the looper member 47 on its pivot 46, raising the point 48 away from the toe 45 of the rigid looper foot; To accommodate the looper foot when it lies below the plane of passage of the needle in loop-presenting position, I form in the surface of the presser foot a recess 78 into which the looper foot may be depressed as shown in Fig. 4.

For a simple and effective take-up action to handle the needle thread in cooperation with the looper mechanism I arrange the take-up arm 80 at the front end of the machine, pivotally mounting said arm as at 81 on the end of a vertical link 82 which is pivoted tothe frame post 16 as at 83 and in the take-up arm intermediate the pivotal point 81 and its acting end I form an aperture or engagement with a writ pin 85 preferably integral with, but eccentric to the axis of, the main shaft 40. Appropriate tension devices and thread guides are provided on the machine, 86 representing a usual tension device from which the thread is run through an aperture on the active end of the take'up 80 and thence beneath a thread guide and brake spring 87, carried by the needle bar, to the needle eye.

In the operation of the machine, as in Figs. 8 and 9, a node of goods vated through the presser foot opening 18 and the needle moving forward penetrates into and emerges from the uppersurface shown thereof, woiking wholly above the presser As the needle advances, the oppooscillating rock shaft 68 carries the to its forward limit 0 foot. sitely 4b and. the foot pass above the needle and ruler the loop. As the needle retracts, wrist pin 67 oscillates toward the position shown in Fi Q passing over vertical center and mg the looper, point structure as a to rise above the work and passaft across the opening in" the presser .foot; the

throw of the'eccentric pin '67 being sufli cient to depress the foot 44 so that its toe -15 lies below the line of passage of the needle in. the recess 78 of the presser foot as shown. in Figs. 2 and 7. During this operation the finger 50 of looper member 47 engages the ram face T17 of arm 76 which restrains it against descent and forces the spreader point 48 to raised position inward from the path of needle travel and above the path of the same. During the last part of this cycle of movement of the looper the feed works to carry the goods toward the rear of the machine so that when the needle starts on its next penetrating stroke the loop Z is expanded as'indicated in Fig. 9; assuming a triangular form with one limb leading from thepoint of emergence of the loop from the work up to the shoulder 49 which is above and inward from the needle path and the other limb of the loop leading below the elongated foot 44, and thence with an upward trend passing below the needle path to the shoulder 49. I find that by such a looper construction I can insure positive presentation of the loop in such spread condition that the needle must pass there through on a penetrating stroke and this regardless of any length of'stitch for which the machine may be adjusted. The elongated foot 14 holds down the lower run of the thread loop in such position that the needle thread may pass thereover regardless of. the length of feed between stitches, even though the feed length be suflicient to carry the point of emergence of the loop being manipulated beyond the end of the presscr foot opening 18. When the needle starts on its next penetrating stroke, the looper point dwells practically stationary until the needle has passed through the thread loop, and then the action of the cam (3.; carries the looper point structure as a whole rapidly out of the loop toward the rear of the machine, so that the take-.up 80, performing its active operation at approximiddle fulcrum of constitution of said tion with the looper bar on which mately this time, in conjunction with the now-forwardly-moving needle, sets the previously laid loop. 1

While I have herein described in some detail a particular embodiment of my invention which I have found to be practically ellicieiit, it am he apparent to those skilled in the art that changes in detail of construc tion might be made without depart I-e from the spirit of my invention and Within the scope of the appended claims,

lVhat I claim is: a

1. In a sewing machine stitch forming mechanism, the nb nation with a needle,

f looper merhar 11, comprising a looper bar structure, a imoldle fulcrum therefor constituting of said her a lever of the first order, means havingficxible connection with said bar for imparting motion to the powerreceiving end thereoi in a planeto give its point-end an in and-out movement across the needle path, and means for shifting'the said lever fore-and-aft, thereby to actuate :iiu bar as a level of the third order. to ma the looper point foreandaft with and flexible connection as afulcrum.

2. In a scrim "hinc stitch forming mechanism, the co ration with a needle, f looper meelumisnri, comprising a looper bar structure, a middle fulcrum therefor bar a lever of the first order, said fulcrum comprising an eccentric oscillating member. means to vibrate the end of said looper on said fulcrum, said means providing a sliding flexible connecsaid bar fulcrums transversely to the middle fulcrum as a lever ofthe third order.

3. A sewing machine stitch forming mechanism comprising in combination a re ciprocating needle, a looper-bar structure coml'irising a lever of the first order, havin; a point structure at one end, ,a movable middle fulcrum for said bar, means for moving said fulcrum up and down and foreand-aft with respect to the line of needle passage and means for moving the power receiving end of said bar in and out with respect to said line of needle passage, trans- 115 vcrscly to the plane of the first said movement, to vibrate said bar on its middle fulcrum.

4. In a slewixg machine stitch forming mechanism, the combi iurtion with a pivoted 12o needle bar. a curved needle. and means for operating the needle bar, of a shaft parallel with the needle bar axis, means to rock said shaft, a fulcrum member eccentrically carried by said shaft, a looper bar struc- 1:5 ture pivoted on and carried by said fulcrum member for vibration in a planeparallel will inc shaft axis and for bodily movement fore-and-aft and upwind-down with said fulcrum member, and means for 1 imparting the stated vibration to said looper bar structure.

5. In a sewing machine stitch forming mechanism, the combination with a pivoted needle bar, a curved needle therein, and means for vibrating said needle bar, of a shaft concentric with the needle bar axis, a fulcrum member eccentrically carried by the said shaft, means to rock said shaft, a looper bar lever of the first order pivotally carried by said fulcrum member, said lever vibratable upon its pivotal axis ina plane parallel with the axis of the shaft and bodily movable fore-and-aft with respect to the line of passage of the needle with said fulcrum member, means for imparting to said looper bar lever the stated vibration working in a plane parallel with the axis of said shaft, and a universal sliding joint between the power-receiving end of said looper lever and said moving means.

6. In a sewing machine, stitch forming mechanism comprising in combination a pivoted needle bar, a shaft parallel with the needle bar axis, a looper bar connected for movement with said shaft, a power shaft, a jack-shaft, gearing connections between said power and .ing

jack-shafts, operatconnections from one end of said jackshaft to the needle bar and operating connect-ions from the other end of said jackshaft to the shaft for the looper bar.

7. In a sewing machine, stitch forming mechanism comprising in combination a pivoted needle bar, a looper-operating shaft, a looper lever eccentrically connected with saidshaft and bodily movable thereby in a plane parallel with the plane of needle bar oscillation, a power shaft and operating connections between said power shaft and the needle bar and looper-operating shaft for simultaneously oscillating said needle bar and said looper-operating shaft in opposite directions through a portion of their throws.

8. A sewing machine stitch forming mechanism comprising in combination a pivoted needle bar, a bodily movable looper, a shaft carrying said looper in eccentric connection therewith for bodily movement, a power shaft, a jack-shaft driven thereby, operating connection between said jackshaft and the pivoted needle bar, and operating connections between said jack-shaft and the oscillating looper carrying shaft, comprising direction reversing gearing and a link connection with the rotating jackshaft.

9. Sewing machine stitch forming mechanism, comprising a needle, means to reciprocate it, a looper structure, means to vibrate said looper structure in and out across the path of needle reciprocation at the ends of its fore-and-aft throw, an os- 1 in; 4:. wmmnvinnqnirl lnnner 'up-and-down in a bodily fore-and-aft, and means for latin said shaft comprising a constantly rotating part and connections between said constantly rotating part and the oscillating shaft including a link crank-connected bodily by oscillation of fsaid'shaft, in forea'nd-aft direction and up'and downfmeans for oscillating said shaft to cause said shaft to dwell at its extreme of oscillation, and means to vibrate said .100 in and out during therespective dive S initS'foreand-a t-movement.

11. In a'sewing machine stitch forming mechanism, a looper for 6-way movement pivoted between its ends, for vibration in one plane, means to vibrate said lever movable only in said plane, a flexible-slide-joint connection between said'moving means and said lever whereon said levermay fulcrum for movement in a plane transverse to its plane of vibration, and means for moving the pivotal axis of said lever bodily to cause movement of said looper, fore-and-aft and plane transverse to said plane of vibration with the joint connection as a fulcrum.

.to the constantly rotating part and .ar-

anism, comprising, in combination,

a needle bar pivoted in saidfframe, alooper carrying shaft parallel with 'the pivotal axis of the needle bar, a fulcrum block eccentrically mounted on said shaft for bodily movement therewith in a plane parallel with the plane of oscillation of the needle bar, a looper pivoted to said block for vibration in a plane transverse to the first said plane, a power shaft, a cam on said power shaft, a lever actuated by said cam, a sliding universal connection between the power applying end of said lever and said looper, a transverse shaft extending through said frame, gearingconnections between said power shaft and transverse shaft, a crank and link connection between said transverse shaft and the needle bar, and connections between said transverse shaft and the fulcrumblock-carrying shaft for oscillating the last said shaft, comprising motion reversing deaQf-center when the fulcrum-carrying shaft-is at its limits of oscillating ip'ivement.

' 13. Sewing machine stitch forming mechanism, comprising in combination with a presser foot a, reciprocating needle working across one side the presser-foot, a looper member working on the same side of the presser foot, means for imparting six-way cyclic motion to said looper member, a secondlooper member carried by the first, and stationary means, acted on by the second said looper men'iber, during its movement with the first said member, for causing opening and closing relative movement if said members, respectively to spread and to take the loop.

14. Sewing machine stitch forming mechanism, comprising in combination a reciprocating needle, and a cooperating looper comprisinga relatively rigid member,means for imparting six-wa y cyclic motion tl iereto including movement fore and aftiof the plane of needle passage, a relatively yielding member carried by said relatively rigid member, and movable with respect to said fixed member to close or open position and fixed cam inrains coacting with said relatively yielding member during its bodily. fore and aft movement with the relatively rigid member,

' arranged to cause relative movement between said two members 15. I Sewing machine stitch forming mechanism, comprising in combination a looper member, providing an elongated foot and toe, an auxiliary looper member, carried by the first, providing a looper point, means normally to hold said point and toe in cooperating closed position ointly to enter a loop, means for moving the first said memher in acyclic course including movement fore and aft with respect to the needletravel, and a stationary cam coaeting with the second said member at one end only of its fore and aft throw to cause its points to separate from the toe to spread the loop.

16. In a sewing machine stitch. forming mechanism, the combination of a looper member having a foot, a coacting pointed looper member bodily movable therewith and movable relative thereto, means to move said members bodily together in a 6-way movement andrelative to each other to present the foot and point jointly above the needle path at one extreme of the 6-way one of said members in a six-way cyclic path and fixed'cam means cooperating with the other member to cause relative movement f between said members in the course of. their bodily displacement, whereby the point/and foot of said members are separated at one end of their throw and are brought together at the other end of their throw.

18. Sewing machine stitch forming mechanism comprising in combination a needle,

looper mechanism provided with an elongated foot and a cooperating point relatively movable to open or closed position, means to operate saidlooper member to cause said foot and point while closed to enter a loop above the needle at one endof their throw and to cause the foot to descend below and the point to stand above the path of needle operation at the other end of their throw. In testimony whereof I hereunto set my hand in the presence of two witnesses.

JAMES VHITELAVV. 1n the presence ot' J. 1). Emmy, L. C. KIN'GSLAND. 

